1) Copy \ paste keyframes, tip from CgTalk forum (thanks to sormint)
There’s an easy way to copy poses in the timeline. If you select a frame (just left click, no need to shift-click) then middle-mouse drag to the frame you want to paste and hit the “S” key. This copies attribute values, not keys, which means it doesn’t matter if you have a key on the frame you are copying from. As far as I know it only works for single keys. I haven’t tried selecting a range of keys with shift-select so I can’t say that would work. Anyways, I use this technique some times to throw in a quick slow in key by selecting a frame or two before the pose and dragging it back so that it takes longer to get there. Or use it to copy keys for a cycle. Sometimes, I’m working away and I realize that I accidentally started posing my character while still on the frame for the previous pose. I don’t want to go to the right frame or I’ll lose my pose and I don’t want to set a pose because it will overwrite the one that’s supposed to be there. So I can just drag over to the frame it should be on and key it there. Then when I scrub both keys will remain and be in the right spot.
2) saving \ loading skin weights – ngSkinTools. It’s a really nice thing for skinning in Maya.